Bubble removal element and immersion cooling electronic device

Abstract

An immersion cooling electronic device comprises a cooling unit, an electronic component, and a bubble removal element. The cooling unit having a housing and liquid contained in the housing, the electronic component being immersed in the liquid, and having a surface that contacts the liquid and that forms bubbles. The bubble removal element includes at least one spiral coil disposed above the surface at a predetermined height not greater than a separation diameter of the bubble, each of the spiral coils having a plurality of coils, wherein a diameter of the coil adjacent to the surface is not greater than a bubble diameter, and a diameter of one of any two of the coils close to the surface is not greater than the diameter of the other one. The bubble removal element can effectively remove bubbles generated from a surface of the electronic component, thereby preventing the bubbles from staying on the surface to form an air film.

Description

Technical Field

[0001] This invention relates to a heat dissipation auxiliary component and a heat dissipation device having the heat dissipation auxiliary component, particularly to a heat dissipation auxiliary component with removable air bubbles and an immersion heat dissipation electronic device. Prior Technology

[0002] Heat dissipation or reaction devices with a two-phase (solid / liquid) interface, such as electrolytic devices or immersion heat sinks, share a common drawback: the reaction or heat dissipation process generates a large number of bubbles on the surface of the components. The longer these bubbles remain, the worse the effect the device achieves. For example, in immersion heat sinks, power components that generate heat are typically immersed in a non-conductive coolant to reduce the high temperatures generated during operation and prevent damage. However, in heat dissipation processes that utilize coolant to exchange heat with electronic components, bubbles are generated on the surface of the electronic components in contact with the liquid due to the temperature rise. Some of these bubbles remain on the surface of the electronic components, and some even accumulate to form an air film, thus affecting heat dissipation and causing heat accumulation.

[0003] The common practice is to change the hydrophilic or hydrophobic properties of the surface of the electronic component in contact with the liquid, so that bubbles can more easily detach from the surface of the electronic component. However, the effect that can be achieved is limited. Therefore, how to design a device to help bubbles detach from the surface of the component more effectively is a problem that technicians in related fields urgently want to improve. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide an immersion heat dissipation electronic device.

[0005] Therefore, the present invention provides an immersion-cooled electronic device, comprising a cooling unit, an electronic component, and a bubble removal component.

[0006] The cooling unit has a housing that defines a chamber and a liquid contained in the chamber.

[0007] The electronic component is immersed in the liquid and has a surface that is in contact with the liquid and forms bubbles. The diameter of the bubble before it leaves the surface is defined as the bubble diameter, and the diameter of the bubble when it leaves the surface is defined as the detachment diameter. The bubble diameter is not greater than the detachment diameter.

[0008] The bubble removal device includes at least one spiral coil disposed above the surface at a predetermined height not greater than the detachment diameter of the bubble. Each spiral coil has a plurality of coils, wherein the diameter of the coil adjacent to the surface is not greater than the diameter of the bubble, and the diameter of any two coils adjacent to the surface is not greater than the diameter of the other coil.

[0009] Another object of the present invention is to provide a bubble removal device for removing bubbles from a surface of a solid element immersed in a liquid. The diameter of the bubble before it leaves the surface is defined as the bubble diameter, and the diameter of the bubble when it leaves the surface is defined as the detachment diameter. The bubble diameter is not greater than the detachment diameter. The bubble removal device includes at least one helical coil and is disposed above the surface at a predetermined height not greater than the detachment diameter of the bubble. Each helical coil has a plurality of turns. The diameter of the turns adjacent to the surface is not greater than the bubble diameter, and the diameter of any two turns adjacent to the surface is not greater than the diameter of the other turn.

[0010] The advantage of this invention is that by setting the spiral coils on the surface of the electronic component that generates bubbles, and adjusting the dimensional relationship between the spiral coils and the diameter of the bubbles, the bubbles can be effectively assisted in detaching from the surface after they are generated, thereby preventing the bubbles from remaining on the surface and forming a gas film. Simple Explanation of the Diagram

[0011] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG1 is a schematic diagram illustrating an embodiment of the immersion heat dissipation electronic device of the present invention; FIG2 is a schematic diagram illustrating the spiral coil of the bubble removal component of the embodiment; FIG3 is a cross-sectional schematic diagram illustrating the detailed features of the spiral coil; and FIG4, (a) is an overheating degree-heat flux curve of specific examples 1, 2 and reference example (copper), and (b) is a critical heat flux bar graph of specific examples 1, 2 and reference example (copper). Implementation

[0012] Before the present invention is described in detail, it should be noted that similar elements are represented by the same numbers in the following description.

[0013] The technical content, features, and effects of this invention will be clearly presented in the following detailed description of the embodiments with reference to the accompanying drawings. Furthermore, it should be noted that the drawings of this invention are only for illustrating the structural and / or positional relationships between elements and are not related to the actual dimensions of each element.

[0014] Referring to Figures 1 to 3, an embodiment of the immersion heat dissipation electronic device of the present invention includes a cooling unit 2, an electronic component 3, a bubble removal component 4, and a fixing unit 5.

[0015] The cooling unit 2 includes a housing 21 that defines a chamber, and a liquid 22 contained in the chamber.

[0016] The electronic component 3 is a power component that generates heat during operation. It is immersed in the liquid 22 and has a surface 31 that contacts the liquid 22 and forms bubbles 99. The diameter of the bubble 99 before it leaves the surface 31 is defined as the bubble diameter r, and the diameter of the bubble 99 when it leaves the surface 31 is defined as the departure diameter R. The bubble diameter r is not greater than the departure diameter R.

[0017] The bubble removal component 4 is positioned above the surface 31 at a predetermined height h by the fixing unit 5, and the predetermined height h is not greater than the detachment diameter R of the bubble 99. The bubble removal component 4 includes one or more spiral coils 41, each spiral coil 41 having a plurality of coils C, and the diameter of any two coils C adjacent to the surface 31 is not greater than the diameter of the other coil, and the diameter of the coil C of each spiral coil 41 adjacent to the surface 31 is not greater than the diameter r of the bubble.

[0018] Furthermore, when the bubble removal component 4 has multiple spiral coils 41, these spiral coils 41 may be dispersed above the surface 31, or they may be adjacent to each other to form an assembly above the surface 31.

[0019] The fixing unit 5 has at least one fixing member 51, and each fixing member 51 extends from either end or side of the corresponding spiral coil 41 and is fixed to the surface 31.

[0020] In this embodiment, the bubble removal component 4 has a plurality of spiral coils 41, which are adjacent to each other to form an assembly, and the fixing unit 5 has a fixing member 51 extending from one side of the assembly and fixed to the surface 31. However, in actual implementation, it is not limited to this.

[0021] Preferably, the vertical length of the spiral coil 41 is not greater than the detachment diameter R, which is beneficial to the short residence time of the bubble 99 after it is driven into the spiral coil 41, so that the next bubble 99 can be detached again.

[0022] In some embodiments, the distance G between any two adjacent spirals C is between 0.05 and 1.5 times the separation diameter R.

[0023] In some embodiments, the distance G between any two adjacent spiral rings C is not less than the pipe diameter W of the two spiral rings C themselves.

[0024] By setting the spiral coils 41 at a height not greater than the break-off diameter R of the bubble 99, and ensuring that the diameter of the spiral coil C of each spiral coil 41 adjacent to the surface 31 is not greater than the diameter r of the bubble, it is beneficial to guide the bubble 99 into the spiral coil 41 when it is generated, thereby reducing the chance of the bubble 99 forming a film on the surface 31 on its own or combining with adjacent bubbles 99 to form a gas film.

[0025] Specifically, in this embodiment, each spiral coil 41 may have the same diameter as shown in FIG2(a), and the spacing G between any two adjacent spiral coils C may be the same; or, as shown in FIG2(b) and (c), they may have different diameters and varying spacing G. More specifically, the spiral coil 41 is divided into a first segment 41a adjacent to the surface 31 and a second segment 41b away from the surface 31.

[0026] The diameters of the spiral coils C of the spiral coil 41 can be distributed in a gradually increasing manner away from the surface 31, but the rate of change of the diameter of any two adjacent spiral coils C in the first segment 41a and the second segment 41b is controlled, as shown in FIG2(b). The spacing G of the spiral coils C is the same, but the rate of change of the diameter of any two adjacent spiral coils C in the first segment 41a is greater than the rate of change of the diameter of any two adjacent spiral coils C in the second segment 41b. In other embodiments, the rate of change of the diameter of any two adjacent spiral coils C in the first segment 41a may also be less than the rate of change of the diameter of any two adjacent spiral coils C in the second segment 41b.

[0027] Furthermore, the spacing G between any two adjacent coils C in the first segment 41a of the spiral coil 41 can be different from the spacing G between any two adjacent coils C in the second segment 41b. As shown in FIG2(c), the diameters of the coils C of the spiral coil 41 are distributed in a gradually increasing manner away from the surface 31, but the spacing G between any two adjacent coils C in the first segment 41a is greater than the spacing G between any two adjacent coils C in the second segment 41b. In other embodiments, the spacing G between any two adjacent coils C in the first segment 41a can also be smaller than the spacing G between any two adjacent coils C in the second segment 41b.

[0028] By further coordinating the changes in the diameter and spacing G of the spiral coils C, the upward pulling force of the spiral coils C on the bubble 99 in the first segment 41a and the second segment 41b is altered, thereby accelerating the detachment of the bubble 99. Furthermore, when the spiral coil 41 is configured with a structure that is narrower at the bottom and wider at the top, the lower half of the bubble 99, upon entering the spiral coil 41, exhibits a cone-shaped lower portion, resulting in a lower radius R2 that is smaller than the upper radius R1. This creates a pressure difference between the upper and lower portions of the bubble 99 (as shown in Figure 3), generating an upward force that drives the bubble 99 away from the surface 31 more effectively, thus achieving the desired bubble removal.

[0029] Furthermore, it should be noted that the purpose of the bubble removal component 4 is to remove bubbles generated on the surface of the solid component in contact with the liquid during operation under two-phase (solid / liquid) environmental conditions. For example, in the immersion-cooled electronic device of this embodiment, the bubble removal component 4 is used to remove bubbles 99 on the surface 31 of the electronic component 3 immersed in the liquid 22 (coolant) in contact with the liquid 22. However, in other embodiments, the bubble removal component 4 can also be applied, for example, to an electrolysis device to remove bubbles that remain on the electrode surface during the electrolysis process, preventing bubble accumulation from affecting the contact area between the electrode and the electrolyte.

[0030] The following specific examples 1, 2 and reference example (copper) illustrate the application of the bubble removal component 4 of the present invention to a heated copper plate. The bubble removal component 4 is fixed to the external surface 31 of the heated copper plate to remove bubbles and measure its heat dissipation related data.

[0031] Specific example 1

[0032] The bubble removal component 4 of this specific example 1 has 7 interconnected spiral coils 41. Each spiral coil 41 has the same diameter and spacing G as shown in FIG2(a), and the vertical length of the spiral coils 41 of this specific example 1 is 1.0 cm.

[0033] Specific example 2

[0034] The structure of this specific example 2 is similar to that of this specific example 1, except that the bubble removal component 4 of this specific example 2 has only 3 interconnected spiral coils 41.

[0035] This reference example shows that no bubble removal element 4 is provided on the surface of the heating copper plate.

[0036] Referring to Figure 4, Figure 4(a) illustrates the relationship between superheat and heat flux. The dashed line represents Zuber's correlation, and the solid line represents Rohsenow's correlation. Superheat refers to the difference between the surface of the heating copper plate and the boiling point of the liquid. The results from Examples 1 and 2 show that, under the same superheat, a greater number of spiral coils 41 results in a greater heat flux, meaning a better effect on heat conduction. This indicates that under the same heating conditions, a greater number of spiral coils 41 leads to better bubble removal, thus providing more effective auxiliary heat dissipation. Furthermore, referring to Figure 4(b), the results show that the growth rate of the critical heat flux (CHF) in Example 1 relative to the reference example (approximately 61%) is greater than the growth rate of Example 2 relative to the reference example (approximately 25%). The critical heat flux (CHF) indicates that the heating surface achieves maximum heat conduction when it is in a state of nucleus boiling, i.e., when a large number of bubbles are generated on the heating surface. If the overheating exceeds the temperature difference corresponding to CHF, it will switch from nucleus boiling to film boiling, resulting in the formation of a gas film on the heating surface, reducing the thermal conductivity and causing damage to the component. Therefore, the results in Figure 4(b) also show that when there are a large number of spiral coils 41, the bubbles generated on the surface of the heating copper plate can be effectively removed, thus achieving better heat conduction. In addition, by combining the data results in Figures 4(a) and 4(b), the appropriate operating temperature range for specific examples 1 and 2 can be obtained, avoiding the chance of film boiling and thus preventing thermal collapse.

[0037] In summary, the bubble removal device and immersion heat dissipation electronic device of the present invention effectively assist the bubble 99 to detach from the surface 31 by installing at least one spiral coil 41 at a predetermined height h above the surface 31 where the bubble 99 is generated, and by designing the detailed structure of the spiral coil 41 according to the bubble diameter r before detachment and the detachment diameter R, thereby avoiding the problem of the bubble 99 remaining on the surface 31 or forming an air film on the surface 31. Therefore, the purpose of the present invention can indeed be achieved.

[0038] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification of the present invention shall still fall within the scope of the patent of the present invention.

[0039] 2: Cooling unit 21: Shell 22: Liquid 3: Electronic components 31: Surface 4: Bubble removal component 41: Helical coil C: Spiral ring 41a: First paragraph 41b: Second paragraph 5: Fixed Unit 51: Fastener 99: Bubbles W: Pipe diameter G: Spacing h: Preset height r: Bubble diameter R: Departure diameter R1: Radius of the upper half R2: Lower half radius

Claims

1. An immersion-cooled electronic device, comprising: a cooling unit having a housing defining a chamber, and a liquid contained in the chamber; an electronic component immersed in the liquid, having a surface that contacts the liquid and forms a bubble, defining the diameter of the bubble before it detaches from the surface as the bubble diameter, and the diameter of the bubble when it detaches from the surface as the detachment diameter, wherein the bubble diameter is not greater than the detachment diameter; and a bubble removal component including at least one helical coil disposed above the surface at a predetermined height not greater than the detachment diameter of the bubble, each helical coil having a plurality of coils, wherein... The diameter of the spiral ring adjacent to the surface is not greater than the diameter of the bubble, and the diameter of any two spiral rings adjacent to the surface is not greater than the diameter of the other one.

2. The immersion-cooled electronic device as described in claim 1, wherein, The distance between any two adjacent spirals is between 0.05 and 1.5 times the separation diameter.

3. The immersion-cooled electronic device as described in claim 1, wherein, At least one of the vertical lengths of the spiral coil is not greater than the break-off diameter.

4. The immersion-cooled electronic device as described in claim 1, wherein, The distance between any two adjacent spiral rings shall not be less than the diameter of the two spiral rings themselves.

5. The immersion-cooled electronic device as described in claim 1, wherein, At least one of the spiral coils includes a first segment adjacent to the surface and a second segment away from the surface, wherein the spacing between any two adjacent spiral coils in the first segment is different from the spacing between any two adjacent spiral coils in the second segment.

6. The immersion-cooled electronic device as described in claim 1 or 5, wherein, At least one of the spiral coils includes a first segment adjacent to the surface and a second segment away from the surface, wherein the rate of change of diameter of any two adjacent spiral coils in the first segment is different from the rate of change of diameter of any two adjacent spiral coils in the second segment.

7. The immersion-cooled electronic device as described in claim 1, wherein, The bubble removal device has multiple spiral coils, and these spiral coils are connected to each other.

8. The immersion-cooled electronic device as claimed in claim 1 further includes a fixing unit for fixing the at least one spiral coil at the predetermined height.

9. The immersion-cooled electronic device as described in claim 8, wherein, The fixing unit has at least one fixing member, each of which extends from either end of the corresponding spiral coil or any of the sides and is fixed to the surface.

10. A bubble removal device for removing bubbles from a surface of a solid element immersed in a liquid, wherein the diameter of the bubble before it detaches from the surface is defined as the bubble diameter, and the diameter of the bubble when it detaches from the surface is defined as the detachment diameter, and the bubble diameter is not greater than the detachment diameter, the bubble removal device comprising at least one helical coil disposed above the surface at a predetermined height not greater than the detachment diameter of the bubble, each helical coil having a plurality of turns, the diameter of the turns adjacent to the surface being not greater than the bubble diameter, and the diameter of any two turns adjacent to the surface being not greater than the diameter of the other turn.

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